Machine-switching telephone system



H. P. CLAUSEN.

MACHINE SWITCHING TELEPHONE SYSTEM.

APPLICATION FILED NOV. 26, 1917.

Patented Aug. 9, 1921.

IIHII bake/War Hen/y P C/ausan mm m P lollll m M- iii UNITE S AT E :HENEY '1'. GLAUSEN, oE MoUN'r VERNON, Ew YORK," ASSIGN'OR 'row srEaN Etna TRIcooMPANY, INCORPORATED, OF NEW Yo uc 2., AcormoRA'rIoN oENEw YORK.

MACHINE-SWITCHING TELEPHONE SYSTEM.

disestablish a connection at the end of conversation. In some systems the control of the release of all switches used in establishing a connection, lies in the hands of the calling party, in other systems either party may disconnect, and instill others both parties to aconnection must replace their receivers to the switchhooks in. order to sever a connection. It is to systems of the latter class that this invention'relates.

, It is obvious in arrangements of this character that at times the switching apparatus and telephone lines used in establishing a connection may be uselessly tied up due to one of the parties abandoning a call or for some other reason neglecting to replace "his receiver to its switchhook. 1

It is the object of this invention tOQPIO- vide a simple and effective means for breaking down such connections where a lineis unduly tied up out of control of its subscriber. p

The invention is illustrated in'the accompanying drawing, which shows diagram-' matically a connection between two 'sub- SCl'lbQIS. .The clrcuits of a connector switch used in the connection embody the principles of the invention and, are shown in full.

In accordance with this invention,-an electromagnetic device of special designgis as sociated with each connector switch. -This device comprises a solenoid and a dashpot and is so constructed as, to operate a plun-' ger by means of impulses,-until this plunger engages a set of contacts which close a re- 7 lease circuitifontheconnector switch. The

circuit for the-operation of this device-is Specification of Letters Patentl Application filed November 26, 1917. vSerial No. 203,979.

Patented the talking position, and the impulses are transmitted, by the manipulation of the sender at either subscribers' station. The device is so adjusted that a predetermined numberof successive impulses, say, tenfwill actuate its contacts. If less than,"say, .ten successive impulses, are sent," the contacts will not be. actuated ;and the plunger will return to'normal. In the event-that one of the parties to a connectionnabandons a call without replacing his receiver to the-switchhook and the other party desires to be freed from this connection in order to make an other call, he has 'butto operate his'dial to, say, the digit 5,an-d then initiate the newy call. The manipulationo'f the: dial to digit- 5 -'will cause one ,of'thebridge relays to re tract and again attract its armature fivetimes. An impulse is sent'to the device uponthe pass-by of the relay contacts oneach movement of the bridge relay, that is, once during attraction and again on retraction so that digit 5 will send ten impulsesJ-i Aug. 9,1921.

AT NT; OFFICE l a I The calling subscribers substation is shown at A and the called subscribers substation at B1 C represents the dashp'ot relay above referred to, and represents other. switching Idevlces used 1n connecting the,

calling subscribers line to-the terminals 38, w

39 of the connector switch;

stood from the followin gdescription of'the operation" of thesystenr- When the subscriber at A removeszhisreceiver from the hook,a-line finder switch at D automatically connects, either. directly or through the- The invention will bemore readily underthe connector. Thereupon a circuit is closed r from battery,- right-hand Winding of relay 2, conductor 23, inner'left-hand normal contact of relay .1, conductor 13, terminal 39, over line A, terminal 38, conductor-12, middle left-hand normal contact of relay 1 and conductor 24Ito; the left-hand winding of relay 2 and groundfto operate relay 2. The operationof relay 2' in turnrc'loses a circuit at its-right-hand armature and front contacttorthewinding ofrelayB to battery and ground. The operation of relay-3 in turn opens atitsleft-hand normal contact a connectiontosprevent the closuretf the release magnetcircnit during the .operation of the connector switch, and closes at its righthand contact a circuit receptive to impulses to operate the switch. The switch is now in position receptive to dial impulses. ,The subscriber at A operates his dial to position the brushes 41, 42, 43 in relation to the group containing the wanted line B. The manipulation of the dial at A causes an opening and closure of the circuit of .relay 2 above traced, a number of times corresponding to the number dialed. Upon each retraction of the armatures of relay 2 a circuit is closed from ground, right-hand armature and normal contact of relay 2, righthand contact of relay 3, conductor 25, lower normal contact of relay 8, conductor 35, winding of low wound relay 5, conductor 34, thewinding of the primary magnet PM, side-switch brush 10 and first positioncontact to battery and ground. The closure of this circuit causes the operation of the primary magnet PM and relay 5. Relays 3 and 5 are slow to release and will not retract their armatures between impulses in a series. The operation of the primary magnet PM causes the rotation of the brushes 41, 42, 43, to their predetermined position. The operation of relay 5 closes at its armature and front contact, a circuit from ground to the winding of the escapement magnet ESC to grounded battery. This circuit is opened at the cessation of the series of im ulses,

thereby deenerigizing the magnet E C and allowing the side switch to move to po-j sition 2.

The subscriber at A now operates his dial to position the brushes 41, 42, 43 upon the terminals of the wanted line. The manipulation of the dial again opens the circuit of relay 2 as before and closes the circuit pre viously traced through relay 5 and conductor 34 through the left-hand contact of relay 6 and the winding of the secondary magnet SM to the side-switch brush 10 and second position contact to grounded battery.

The intermittent closure of this circuit operates relay 5 and'the secondary"magnet,'

thereby stepping the brushes to their predetermined line contact and energizing the magnet ESC.

Upon the cessation of the series of'impulses relay 5 releases, and closes a connec tion from grounded battery, the winding of magnet ESC, the normal contact of relay 5,

conductor 33, the right-hand winding o'f re lay 6 and its inner normal contact, sideswitch brush 9 and second position contact,

conductor 21, brush 43 to test the lineflter minal 22. If the line to subscriber B is busy,

contact 22 will be "grounded and a circuit willbe closed through relay 6 and'magnet ESC above traced, thereby holding magnet ESC operated and operating relay 6to lock up through its inner armature and front contact, conductor 31 and off-normal con- .6 opens at its left-hand contact, a circuit to prevent further operation of the secondary magnet SM, .and closes at its right-hand armature and front contact, a"circuit from ground, transformer coil 45, conductor 30, conductor 15 and the left-hand winding of relay 1 to grounded battery. The closure of this circuittransmits, by induction, a tone indicating the busy condition of the line to the calling party A, who thereupon replaces his receiver to the hook and releases his connection as will be shown later. If, however, the line is not busy, the circuit through relay 6, since no ground isfound on contact 22, will remain open and the release of the magnet ESC will allow the side switch to pass to position 3.

In side-switch position 3 a'circuitis closed from ground through side-switch brush .9 and third position contact, conductor 21 to brush 43 holding the called line busy, and r through the winding of relay8,conductor 46, the side-switch brush'lO and third position contact to grounded battery. The operation of relay 8 closes circuit to signal the called party as follows. Relay? is operated intermittently by means of interrupter 44. lVheu operated, relay 7 closes acircuit from an alternating current supply atits front contact, through its armature, conductor 37,

.inner'arinature and normal contact of relay 4, conductor '17, armature and contact third from the bottom of relay 8, conductor'19, brush 42 over'the subscribers line B, brush 41, conductor 18,'upper armature and contact of relay 8, conductor 16,'upper armature amlnornial contact of relay'4, through the upper winding of relay 4 'tobattery.

. ringing and its operating circuits at its upper and inner normal contacts, and closes abattery feed circuit to the called line as follows: fromgrounded battery, left-hand winding of relay 1, conductor 15, inner armature and front contact of relay 4, conductor 17, armature and contact third from the bottom of relay 8, conductor'lQ, brush 42 over the line of subscriber B,- brush 41, conductor 18, upper armature and con-v tact of relay 8, conductor 16, upper arma-' ture and front contact of relay 4, conductor14, the right-hand windingof relay 1, conductor 29, bottom contact of relay'4,

conductor 31, through the oil-normal contact ON to ground. The closure of this circuit operates relay 1 and completes the talking connections between the two parties. v

Previous to the operation of relay 1 the control of the release of all switches used in the connection was in the hands of the sub 'scriber at A. By 'replacing'his receiver to the switchh'ook, he deenergized relay 2 and in turn relay 3, closing a path from ground, the left-hand armature and normal contact of relay 3, conductor 26, off-normal contact ON, conductor 27, right-hand armature and normal contact of relay 1, through the winding of release magnet RM to battery, thereby restoring the connector switch to normal. the line finder at D is local previous to the operation of relay 3. When relay 3 is operated it closes at its left-hand front contact a circuit from ground over conductor20 and contact 40 to assume the release control of the switch or switches at D.

Subsequent to the operation of relay 1 the release control is under the joint control of both parties at A and B, except for the arrangement hereinafter disclosed as the essential part of this invention. From the above description it is apparent that in'or der to free the switches used in the connection established, or to use either line A or B to originate or receive other calls, it is necessary to have the receivers of both subscribers sets on their switchhooks at the same time. As stated above this does not always occur when desired by either party, but by the additional arrangement, when one party desires to free his line, he dials say five, thereby causing the intermittent opening of his line and the retraction and attraction of the armature of relay 1 in the case of the called party, or relay 2 in the case of the calling party, to send impulses from the left-hand armature and both contacts (at the time in their movement when all are together), of relays 1 and 2 respectively over conductor 25, side-switch brush 11 and third position contact through the winding of device C to grounded battery.

The operation of the lunger of device 0 over ten steps actuates its contacts to cause the release of the connector switch, by closing a circuit from ground over the top contact or device 0, conductor 26, lower contacts of off-normal contact ON, conductor 47, the lower contacts of device C, conductor 28, through the winding of release magnet RM to grounded battery.

The operation of release magnet RM by releasing the connector, frees both parties so that they may originate and receive calls independent of each other.

What is claimed is:

1. In a machine switching telephone sys tem, calling and called subscribers"lines, au-

The'control of the release of to release saidconnector and auxiliary means" controlled by a predetermined series oi line interruptions for actuating sa1d device.

2. In a machine switching telephone system, calling and called telephone lines, automatic switches including a connector for connecting said lines, a calling and a called line relay for said connector, a release magnet for said connector, a switching device for said connector, and means responsive to a series of closures of the contactsot either of said line relays for rendering said switching device effective to operate said release magnet.

3. In a machine switching telephone system, a calling and a called subscribers line, means including a connector switch for connecting said lines, a release magnet for said connector, an impulse counting device, and means responsive to a predetermined number of impulses for rendering said counting device effective to operate said release magnet.

1. In a machine switching telephone sys tem, a calling and a called telephone line,'a connection including a connector switch between said lines, means under the joint control of said calling and called lines for disestablishing said connection, and other means including a timing device under control of either said calling or said called line for disestablishing said connection.

.5. In a machine switching telephone system, a calling and a called line, a connection including automatic switches between said lines, means including a release magnet asso ciated with one of said switches for sever- 111g said connection when the circuits of both of sa1d lines are open, other means associated with said one of said switches under the control of either line for severing said connection when neither of said line circuits 7 is open.

6. In a machine switching telephone system, calling and called subscribers lines, means including a connector switch for interconnecting said lines, a'magnet, means to restore said connector switch to its normal position as a result of a single energization automatic switches including a connector for i lnterconnecting sa1d lines, of a SWltChlIlg device, means under control of either line, when sa1d connector is set, for sending 1mpulses to said switching device, and'means under the control of said switching. device when operated to a predetermined position for effecting the release of said connector.

8. In a machine switching telephone systern, calling and called subscribers lines, automatic switches including a connector for interconnecting said lines, release means normally under the joint control of a calling and a called subscriber to cause the release of said automatic switches, and auxiliary release means under the control of either subscriber for causing the release of said switches.

9. In a machine switching telephone system calling and called subscribers lines, au-- tomatic switches including a connector for interconnecting said lines, release means for tem calling and called subscribers lines, 2111- tomatic switches for interconnecting said lines, a controlling deviceunderthe control of either subscriber, said controlling device being operative after connection has been established, and means to actuate said controlling device in response to a predetermined series of line interruptions. I

In-witnesswhereof I hereunto subscribe my name this 22nd day of November, A. D. 1917. a i

HENRY P. CLAUSEN. I

to a predetermined series of line interrup 

